760 



(genus XXVII. 



TROCHUS: 



SHELL UNIVALVE, SPIRAL, AND NEARLY CONICAL; 

 APERTURE SOMEWHAT QUADRANGULAR, OR ROUND- 

 ED WITH THE UPPER SIDE TRANSVERSE AND CON- 

 TRACTED ; PILLAR OBLIQUE. 



Subdivisions. "{ 



* Umbilicated and erect. 

 * * Imperforate and erect. 

 *** Tapering, with the pillar exserted, and the 

 shell falling to one side when placed upon its 

 base. 



* Umbilicated and erect. 



NiLOTicus. 1. Shell conical, nearly smooth, and 

 the whirls flattish ; inner lip nearly entire. 



Trochus Niloticus. Linnceus S^st. Nat. p. 1227. Born 

 Mus. p. 327. Chemnitz, v. p. 76. t. 167. f. l605, andt. 

 168. f. 1614. Schroeter Einl. i. p. 647. Gmelin, p. 

 3565. Schreibers Conch, i. p. 239, Lamarck Si/st.des 

 Jnim. p. 86. Brookes s Introd. p. 123. t. 7. f. 93. 



Le Grand Sabot. Favanne, ii. p. 299, and p. S55. t. 12. 

 f. B 1. 



Bonanni Rec. and Kirch. 2. f. 102. Lister Conch, t. 617. 



+ Trochus novus, p. 3577, and T. PulUgo, p. 3585, of Gmelin, are too doubt- 

 fnl to be retained 5 and T. Schroeteri, p. 3575, and T.ferruginevSf p. 3577, are 

 fossil species. 



